From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EA506C433E9 for ; Fri, 5 Mar 2021 14:30:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B6DEA6509A for ; Fri, 5 Mar 2021 14:30:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231253AbhCEO34 (ORCPT ); Fri, 5 Mar 2021 09:29:56 -0500 Received: from mail.skyhub.de ([5.9.137.197]:49364 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230415AbhCEO3s (ORCPT ); Fri, 5 Mar 2021 09:29:48 -0500 Received: from zn.tnic (p200300ec2f0b9500a5847b5a228c2b11.dip0.t-ipconnect.de [IPv6:2003:ec:2f0b:9500:a584:7b5a:228c:2b11]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 378C51EC0521; Fri, 5 Mar 2021 15:29:46 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1614954586; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=756DJLydScKg6OQ7shRw8IU5LHdGM90c3wF/c6DK94s=; b=hB7qolct0HXVDkhC+NG1uce7LdVUT17tmjPoMVViUOt2acE0eZclGgP6iTc6kLwqmWh5zz WXVbm2MGRnH4V8aBErUPvI2qeTMbqEQUFgpMTGb/KqMEER4gscnxIleMXQj/axZ83IpEqn 6P/a5HbB25LXW8wJeDLnwpqgIgh3j4k= Date: Fri, 5 Mar 2021 15:29:40 +0100 From: Borislav Petkov To: Yu-cheng Yu Cc: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V. Shankar" , Vedvyas Shanbhogue , Dave Martin , Weijiang Yang , Pengfei Xu , Haitao Huang Subject: Re: [PATCH v21 10/26] x86/mm: Update pte_modify for _PAGE_COW Message-ID: <20210305142940.GC2685@zn.tnic> References: <20210217222730.15819-1-yu-cheng.yu@intel.com> <20210217222730.15819-11-yu-cheng.yu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210217222730.15819-11-yu-cheng.yu@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Wed, Feb 17, 2021 at 02:27:14PM -0800, Yu-cheng Yu wrote: > @@ -787,16 +802,34 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) > */ > val &= _PAGE_CHG_MASK; > val |= check_pgprot(newprot) & ~_PAGE_CHG_MASK; > + val = fixup_dirty_pte(val); Do I see it correctly that you can do here and below: /* * Fix up potential shadow stack page flags because the RO, Dirty PTE is * special. */ if (pte_dirty()) { pte_mkclean(); pte_mkdirty(); } ? That fixup thing looks grafted and not like a normal flow to me. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette